Segment Maps

The plugin currently supports US maps. Segement maps take as input 4 columns: start latitude , start longitude, end latitude, and end longitude of the segment. The model and data styles for the subsequent examples are:

define airports is (explore 'malloy-data.faa.airports'
  primary key code
  airport_count is count(*)
);

define flights is (explore 'malloy-data.faa.flights'
  primary key id2

  origin_code renames origin
  destination_code renames destination
  origin is join airports on origin_code,
  destination is join airports on destination_code

  flight_count is count()

  routes_map is (reduce
    origin.latitude
    origin.longitude
    latitude2 is destination.latitude
    longitude2 is destination.longitude
    flight_count
  )


);

and data styles are

{
  "routes_map": {
    "renderer": "segment_map"
  }
}

Run as a simple query

Departing from Chicago

explore flights : [dep_time : @2003-02, origin.code : 'ORD']
| routes_map

Run as a nested subtable

explore flights : [dep_time : @2003-02, origin.code : 'ORD']
| reduce
  routes_map

routes_map

Run as a trellis

By calling the configured map as a nested query, a trellis is formed.

explore flights : [dep_time : @2003-02, origin.code : 'ORD']
| reduce
  carrier
  flight_count
  routes_map

carrier	flight_count	routes_map
UA	9,443
AA	7,255
MQ	4,975
DH	3,906
NW	702

Run as a trellis, repeated with different filters

explore flights : [dep_time : @2003-02]
| reduce : [origin.code : 'ORD'|'SFO'|'JFK']
  carrier
  flight_count
   ord is routes_map : [ origin.code: 'ORD']
   sfo is routes_map : [ origin.code: 'SFO']
   jfk is routes_map : [ origin.code: 'JFK']

carrier	flight_count	ord	sfo	jfk
UA	13,584
AA	9,271
MQ	5,885
DH	4,332
OO	2,338